Pakistani officials say a suicide blast targeting a government office in the northwestern province of Khyber Pakhtunkhwa has killed one person and wounded 17 others.

Police said the April 19 attack took place at the Excise and Taxation Department in the town of Mardan, some 50 kilometers northeast of the region's main city of Peshawar.

District police chief Faisal Shahzad said the bomber arrived at the scene on foot and opened fire with a gun before detonating his explosives vest.

He said three of the wounded were in critical condition.

No group immediately claimed responsibility for the attack, which comes a day after the military announced the successful completion of a large-scale operation against militants in the neighboring North Waziristan tribal region bordering Afghanistan.